There has long been interest in developing thermoplastic resins that can resist burning. A specific area of concern is in developing plastics for transportation applications, such as rail cars and airplanes. Various evaluation techniques have been developed to test the effectiveness of such thermoplastic materials, for instance Federal Aviation Regulation (FAR) 25.853. In this test, sometimes referred to as the Ohio State University (OSU) rating, the amount of energy released after 2 minutes and the peak heat release energy are measured. Lower heat release values are desirable.
For many aerospace and transportation applications, materials are required to have a rating of 65/65 (2 minute heat release/peak heat release) or less to be compliant with the standard. In several applications, a rating of 55/55 or less is required with 40/40 being a preferred rating with standards expected to become more stringent in the near future. In general, it is highly desirable to have a material demonstrate a resistance to burn and achieve low OSU ratings. In addition, the time it takes to obtain peak heat release is another material characteristic that has significance since it correlates to the time people, such as passengers, crew, and others, have to flee the hazardous conditions.